Surface Of Substrate Integrated Waveguide Research Articles

A Planar SIW-Based Mm-Wave Frequency-Scanning Slot Antenna Array With No Scan Blindness at Normal

Planar antenna reflectors are the modern design trend of both multibeam and frequency-scanning antenna arrays. The planar implementation of reflectors is typically performed using substrate-integrated waveguide (SIW) technology. A reflector’s profile can be different from the canonical one (parabolic, elliptic, hyperbolic, etc.) because of the effect of spatial dispersion of the reflection coefficient of the SIW-based surface. It should be synthesized considering the magnitude and argument of the field reflected from such a surface to maximize the efficiency of the reflection. In this article, we present a planar millimeter-wave (mm-wave) slot antenna array with SIW-based horn–reflector feeding. We analytically formulate the optimization of the SIW surface dimensions while accounting for the spatial dispersion of the reflection coefficient. We minimize the dimensions of the planar horn–reflector feeding. Finally, we demonstrate that using a dual-slot radiating element, and we can avoid the effects of scan blindness along the normal direction. A prototype has been built and a good agreement has been achieved between the measured results and the predicted results based on calculations. The prototype achieved ±17° beam scanning within 16% of the operational frequency range, with no scan blindness along the normal direction.

Design and implementation of compact tri- and quad-band SIW power divider using modified circular complementary split-ring resonators

AbstractThis paper presents a miniaturized tri- and quad-band power divider (PD)based on substrate integrated waveguide (SIW). By adopting different types of modified circular complementary split-ring resonators on the top surface of SIW, multiple passbands are generated propagating below the SIW cut-off frequency. The working principle is based on evanescent mode propagation that decreases the operating frequency of the PD and helps in the miniaturization of the proposed structure. The operating frequency of the proposed PD can be individually controlled by changing the dimensions of the resonator. To verify the proposed concept, a tri-band and a quad-band PD exhibiting 3 dB equal power division at 2.41/3.46/4.65 GHz and 2.42/3.78/4.74/5.8 GHz are designed using the full-wave simulator, validated through circuit model, fabricated and experimentally verified. The measured results agree well with the simulations. The proposed PDs have good performance in terms of reasonable insertion loss, isolation, minimum amplitude and phase imbalance, smaller footprint, easy fabrication and integration. The size of the fabricated prototype is 18.3 mm × 8.4 mm, which corresponds to 0.205λg × 0.094λg, λg being the guided wavelength at the first operating frequency.

Broadband substrate‐integrated waveguide‐fed endfire metasurface antenna array with gain enhancement

A broadband substrate-integrated waveguide (SIW)-fed endfire metasurface antenna array with improved gain centralisation radiation pattern is proposed in this paper. The metasurface is composed of 3 × 3 rectangular patches distributed on both the upper and lower sides of a single-layer substrate. For wideband endfire radiation, an open-end SIW on the metasurface side feeds the antenna. To improve front to back radiation and ration matching characteristics, one C-shaped slot is etched on the top surface of SIW. Two L-shaped metal walls composed of metalized via holes are employed to centralize radiation pattern and reduce both the side lobe and back lobe levels. In addition, the gain of the antenna is enhanced more than 1.6 dBi. To validate this design, a 1 × 8 uniform excitation array is proposed and fabricated, containing three SIW T junctions and four Y junctions. The whole dimension is 7.33λ0× 3.82λ0 × 0.06λ0. Measurement results imply that an 7.5 to 13.05 GHz (54%) impedance bandwidth can be achieved with the maximum gain of 14.9 dBi.

Design of a wideband substrate integrated waveguide antenna with high‐gain employing two bow‐tie‐shaped slots

In this work, a compact antenna employing the substrate integrated waveguide (SIW) technology is investigated to achieve the characteristics of wideband and high gain. A pair of novel elliptical patches, which operate as an electric dipole, are loaded on the upper surface of the antenna. Two bow-tie-shaped slots are etched in parallel on the upper surface of SIW to obtain the features of magneto dipole and wideband. Combined with the low profile character of the SIW, the low cost of printed circuit board technology and the broadband characteristic of magneto-electric (ME) dipole, a 1 × 8 SIW ME-dipole antenna array is proposed and fabricated. The experimental result of the proposed prototype shows that the 10 dB impedance bandwidth is 42.3% from 19.4 to 29.8 GHz, which is basically consistent with the simulated result. Moreover, the antenna gain up to 14.6 dBi and the radiation efficiency higher than 82.6% are also obtained during the experiment. In the whole resonance band, excellent directional radiation, cross-polarisation level <−25 dB and gain fluctuation <2.7 dB all suggest that the array can be applied to a fifth-generation wireless network.

An SIW antenna utilizing odd‐mode spoof surface plasmon polaritons for broadside radiation

In this article, a substrate integrated waveguide (SIW) antenna utilizing odd-mode spoof surface plasmon polariton (SSPP) for broadside radiation is proposed. Double gratings are etched on the top surface of SIW and the SSPP odd-mode is excited on this hybrid SIW-SSPP structure. The proposed SIW antenna has open-circuit termination and can realize broadside radiation. A prototype of the SIW-based odd-mode antenna is fabricated. Reasonable accordance is achieved between measured results and simulated results. The antenna impedance bandwidth is about 5.5% (12.4~13.1 GHz) with |S11| < −10 dB. Stable broadside radiation is also realized within the operating band of 12.3~13.3 GHz and the measured gain varies from 5.66 to 6.34 dB in the frequency band. The proposed broadside radiation antenna is suitable for wireless communication systems due to its compact structure and good radiation performances.

Balanced Diplexer Based on Substrate Integrated Waveguide Dual-Mode Resonator

This article presents a novel balanced diplexer based on substrate integrated waveguide (SIW) dual-mode resonator. The six-port model has been introduced in this article to achieve the conversion of S-parameters between balanced and unbalanced devices. The SIW dual-mode resonator with common-mode (CM) rejection capability is able to restrain CM signal in the passband of the diplexer. Moreover, the CM rejection performance is improved by etching the slotline on the surface of SIW without changing the transmission of the differential-mode (DM) signal. A diplexer with lower and higher channels centered at 8.8 and 9.4 GHz, with a 3-dB FBW of 4% and 4.8%, respectively, is designed and fabricated to verify the proposed concept. The measured results show that the CM rejection is greater than 42/45 dB and the DM isolation between the lower and higher channels is greater than 35 dB in passband, which shows good agreements with simulations.

A hybrid substrate-integrated waveguide and spoof surface plasmon-polariton one-layer dual bandpass filter formed by resonant tunneling effect

In this paper, we present a novel dual-bandpass filter based on the substrate-integrated waveguide (SIW) and spoof surface plasmon-polariton (SSPP) hybrid structure. In this design, periodic subwavelength H-shaped units are etched on the top SIW surface to support SSPP mode. The dispersion and transmission characteristics of the proposed SIW–SSPP filter are analyzed. The dual-bandpass feature is observed for resonant tunneling of the H-shaped elements, and the passbands can be controlled easily by adjusting the filter parameters. Simulated and measured results demonstrate excellent transmission performance of the proposed filter.

Design and Analysis of 150° Bend SIW and Corrugated SIW Bandpass Filter with Multiple Transmission Zeroes Using Reactive Periodic Structures Suitable for Microwave Integrated Circuits (MICs)

Microwave multi-band bandpass filter using substrate integrated waveguide (SIW) and corrugated SIW (CSIW) over Neltec NH9320 with dielectric constant of 3.2, thickness 30 mil and loss tangent tanδ = 0.0024 are presented in this paper. Firstly, 150° bend in the SIW BPF has been provided in SIW multi-band filters in view of its overall size reduction compared to planar un-bend structures and integration ability as required in microwave integrated circuits. Secondly, Reactive periodic slots are introduced over the SIW surface to obtain multiple transmission zeroes within the passband. These slots are bend to 150° in alignment to the 150° bend within the waveguide section. The method presented is further extended for designing CSIW multi-band BPF. Impacts of several parameters of the periodic slots (which are also 150° bend in accordance with the SIW structure) are analyzed. The measured results ensure improved filter performance like low reflection as well as improved isolation. The angular bend used in the BPF enables it to be integrated with other planar circuits within the same PCB material. Passbands obtained within the microwave Ku-bands are suitable for use in Direct Broadcasting Satellite communication systems.

Substrate Integrated Waveguides Structures Using Frequency Selective Surfaces Operating in Stop-Band (SBFSS-SIW)

A novel Substrate Integrated Waveguide (SIW) is proposed using Frequency Selective Surfaces (FSS) operating in Stop-Band (SBFSS-SIW) as metal conductor plates. These structures preserve the propagation properties and the dimensions of the conventional SIW, and have periodic isolated pads that could allow the direct integration of biased active and passive devices on the SIW surface. A set of SBFSS-SIW for X-band have been designed, simulated and experimentally measured to demonstrate that SBFSS-SIWs can behave similar to conventional SIW structures when FSS cells are optimized to work far from its resonance frequency.

A Digital SIW Phase Shifter Implemented by Switching Transverse Slots via PIN Diodes

AbstractA new idea of Substrate integrated waveguide (SIW) based digital phase shifter by controlling the transverse slots etched over the top metallic surface of SIW is proposed. A PIN diode is mounted on each transverse slot. Slots are made “enabled” or “disabled” by switching the state of PIN diode. A detailed explanation and demonstration is presented in this paper. As a result, a digital four bit phase shifter can be realized. Furthermore, equivalent circuit model for proposed device has also been discussed. Insertion loss is as low as 1.5 dB for a wide bandwidth of 31% (6.75–9.25 GHz), with a phase imbalance of ±4° and amplitude imbalance of ±0.5 dB. Simulation results agree well with the measured results.

Planar high gain antenna for 42.0 GHz Q‐LINK PAN system

ABSTRACTA high gain planar array antenna is reported in this article for recently proposed 42 GHz Q‐LINK PAN wireless communication system. The substrate integrated waveguide (SIW) technique is deployed for the antenna array. Three types of power divider are used in the design to achieve a 30‐dB Taylor aperture distribution. Longitudinal slots etched on the broad surface of SIW are studied with an equivalent circuit. A high gain prototype which used 16 × 16 slots is designed with a center operation frequency of 42.5 GHz. For the measurement, a traditional rectangular waveguide to SIW transition is designed to feed the prototype. The low‐cost printed‐circuit‐board technology is used to fabricate the designed prototype, and the antenna is measured in a millimeter‐wave anechoic chamber. The measurement results show that the prototype can be operated from 41.5 to 43.7 GHz with a return loss larger than 10 dB. It has a maxim gain of 27.0 dB at 42.3 GHz. Low sidelobes of 26.3 and 17.3 dB are obtained for 42.5 GHz E‐plane and H‐plane radiation patters, respectively. © 2014 Wiley Periodicals, Inc. Microwave Opt Technol Lett 56:2098–2103, 2014

Substrate integrated waveguide negative-order resonances and their applications

A family of substrate integrated waveguide (SIW) negative-order resonances and their applications to miniaturised antennas and filters are investigated and presented. These metamaterial resonators are realised by etching the interdigital slot on the surface of SIW with varied boundary conditions. The slot acts as a series capacitor along with the waveguide inherent shunt inductor achieving a composite right/left-handed functionality. These resonances are generated below the characteristic waveguide cut-off frequency and are independent of the dominant TE10 mode. The properties of these different resonances, which are characterised by half-wavelength or quarter-wavelength resonances, are discussed and compared. According to their characteristics, different applications are investigated. First, miniaturised waveguide slot antennas based on the first-order resonance are discussed. These antennas provide relatively high radiation efficiency and regular radiation patterns while keeping a low profile. Secondly, compact waveguide filters are proposed and presented. The simulated and measured results for these filters are provided. These metamaterial filters are showing advantages in terms of low-profile, high stopband rejection, easy fabrication and integration with other circuits.

A novel bandpass filter based on complementary split rings resonators and substrate integrated waveguide

AbstractOne novel bandpass filter implemented with combination of two different structures‐complementary split rings resonators (CSRRs) and substrate integrated waveguide (SIW) is proposed in this article. Several CSRRs are etched on the surface of SIW to form the stopband with very sharp rejection. One prototype was fabricated, the measured results indicate 30% passband (at −15 dB return loss), the rejection band ranges from 6.4 GHz to 7.8 GHz, about 20% bandwidth at −20 dB rejection, the maximum rejection even reaches 50 dB. The rejection skirt is very sharp, only 18 MHz. © 2008 Wiley Periodicals, Inc. Microwave Opt Technol Lett 50: 699–701, 2008; Published online in Wiley InterScience (www.interscience.wiley.com). DOI 10.1002/mop.23182